Vibrator



Patented Aug. 27, 1946 UNITEDv STATES PATENT OFFICE vIBRA'roR Richard H. Whitehead, New Haven, Conn. Application September 16, 1939, Serial No. 295,248

3 Claims.

This inventionrelates to a vibrator element for use in rapid timing mechanisms, particularly where the timing mechanism is to be subjected to strong forces of rotation as for example timing mechanisms employed for time fuses.

In a mechanism of this kind, that is in time fuses, the vibrator element is preferably placed at the exact axis of the fuse so that the force of rotation will act symmetrically upon it. Such vibrators have been provided comprising a single straight strip of spring material extending on both sides of the center line and having the length thereof controlled to vary the timing of the fuse. Such vibrators, however, are subject to unknown and uncalculable force when the fuse is fired with the shell by reason of the fact that the propulsive charge introduces strong force along the axis of the fuse and rotational accelerational forces introduce complications. These forces are very large by reason of the fact that the fuse must attain a. rotational speed of 12,000 to 24,000 revolutions per minute during the brief interval while the projectile is within the bore of the gun.

It is an object of this invention to provide a vibrator which will maintain a uniform timing under all conditions of operation in the fuse and notwithstanding the large force to which it is subjected.

It is a further object to provide a fuse which can be timed by the rotation of a, single element.

The invention accordingly comprises an article of manufacture possessing the features, properties and the relation of elements which will be exemplified in the article hereinafter described and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description, taken in connection with the accompanying drawing, in which:

Fig. 1 is a plan view of an escapement embodying this invention.

Fig. 2 is a section on the line 22 of Fig. 1.

In the figure the characters A, B, C and D designate four plates, these being four of the plates of which the frame of the fuse itself is formed, the other plates not being illustrated because they form no part of the specific invention here disclosed.

The lower plate A is cut out as shown at In to receive an escapement wheel II which is pivoted in a bridge l2 in the plate A below the cut out portion and is pivoted in its upper end in the plate D at apoint not illustrated.

The plate B is thinner than the plates A, C and D and has a portion l3 over-hanging the edge of the escapement wheel II and this over-hanging portion is connected across the center of the plate to the other side of the plate at M to form a bridge l5 which carries a bearing l6 for a pivot ll of a shaft l8 which carries the vibrator l9. This vibrator 19 carries a pair of downwardly extending verge pins 20 and 2! which extend on opposite sides of the bridge [5 into the path of the teeth 22 of the escapement wheel I I so that the vibration of the vibrator will move the verge pins to release the escapement wheel one tooth at a time in the usual manner. The vibrator itself is preferably composed of two outwardly extending arms 23 and 24 which are balanced against each other and move in a cut out portion 25 in the plates C and D.

The vibrator has an upper pivot 26 which has bearing. in another superposed plate which is omitted for the sake of clearness.

In accordance with this invention th vibrator I9 is controlled by a hair spring 21 of hair pin form having its doubled end looped around a pin 28 carried by plate B having its legs extending on opposite sides of the shaft l8 and having its free ends attached to a block 29 slidable in a slot 30 in the plate A and having its position controlled by a radially disposed screw 3! screw threaded into the block 29 and having an enlargement 32 fitting within a recess 33 in the plates A and B. This recess is of such a character as to take the end thrust of the screw and permit the hair spring to be brought under tension thereby.

As illustrated the block 29 has a lower portion 34 of more or less square shape, fitting within the slot 30 and having an upper portion 35 provided with a recess 36 adapted to receive both ends of the free ends of the hair spring 21 and preferably these free ends are turned outwardly as shown at 38. A wedge member 39 may be driven between the free ends of the spring 21 to hold the same in place and simultaneously to bear against the bent over ends 38.

The shaft I8 is provided with projections 40 which extend outwardly on opposite sides of the axis and which are so positioned that with the vibrator in the neutral position these projections lie between the arms of the spring 21, one on each side of the center line. Any movement, however, of the vibrator will cause the projections 40 on one side to bow one leg of the spring 21 outwardly on one side and to bow the other side of the spring outwardly in the opposite direction against the resiliency of the spring and 3 against the tension imposed on the spring by the screw 30. This resists the movement of the vibrator and tends to restore it to neutral position.

The period of vibration of the vibrator is of course determined by the weight of the vibrator and by the resilient pressure of the spring 21 upon the projections =40. This timing may be altered for adjusting purposes by screwing the screw 3| outwardly to impose more tension upon the spring arms or inwardly partially to relieve the said tension.

From the foregoing it will be clear that by reason of the fact that the spring is held under tension by the screw 3|, the weight of the material of the spring 21 may be materially reduced from that which would ordinarily be required, thus reducing the friction of the device and this lightening of the hair spring as well as the construction of the device tends to make the vibrator more nearly free from the rotational forces above referred to.

' This device is, moreover, simple to construct andlreliable in operation.

Since certain changes may be made in the above construction and different embodiments of the invention could be made Without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A vibrator pivoted for vibration and having a flattened portion, a looped hair spring embracing said flattened portion in position to engage said flattened portion resiliently to resist rotation of the vibrator and means to impose tension on said spring.

2. A vibrator element for time fuses or the like adapted to regulate the speed of movement of a time fuse by regulating the speed of revolution of an' escapement wheel comprising in combination a vibratorelement constructed and arranged to operate verge pins in the path of the escapement wheel and having projections on opposite sides of its axis, a looped hair spring embracing said projections and means to impose tension upon said hair spring, 7

3. A device in accordance with claim 2 in which the portions of the looped hair spring are parallel to and substantially in contact with the surface of said flattened portion whereby on rotation of said vibrator the outer edges of said flattened portion engage said hair spring.

RICHARD H. WHITEHEAD. 

